Adjusting and locking device for chuck-jaws



ADJUSTING AND LOCKING DEVICE FOR CHUCK JAWS'.

UNITED STATES I PATENT` (OFFICE.

HANS C. ELVERS, OF MADISON, W'ISCONSIN, ASSIGNOR TO GISHOLT MACHINE COM- PANY, OFiMADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

ADJUSTING AND LOCKING DEVICE .FOR CHUCK-JAWS.

Specification of Letters Patent. Patented July i2, 1921.

Application led February 12, 1921. Serial No. 444,334.

T0 all whom t may concern:

Be it known that I, HANS C. ELvEns, a citizen of the United States, residing at Madison, in the county of Dane and State of l/Visconsin, have invented certain new and useful Improvementsin Adjusting and Locking Devices for Chuck-Jaws, of which the following is a specification.

This invention relates to improvements in chucks for lathes and similar machines employing chucks, and has reference more particularly to van improved device for adjusting and locking the jaw base and jaw on and to the jaw carrier of the chuck. In

many chucks the in and out adjustment of the jaw base and jaw on the jaw carrier is effected by a screw, and in such constructions it has been found necessary to provide means for locking the screw against turning movement under the thrust of the chuck jaw.

The principal object of the present invention is to provide an adjusting screw of such a character that it may readily be made selflocking against accidental turning under the thrust of the chuck jaw, to which end the adjusting screw is made in two endwise abutting sections and provided with means by which both sections may be simultaneously and equally turned to effect the adjustment of the jaw, and then one section may be turned relatively to the other to thereby bind the threads of the screw against the threads of the jaw with sufficient friction to avoid danger of accidental turning.

My invention, its structural' features, and mode or principle of operation will all be readily understood and appreciated by those skilled in the art as the invention becomes better understood by reference to the accompanying drawing7 in which I have illustrated one practical and approved embodiment of the invention, and in which- Figure 1 is a longitudial section through a jaw carrier, jaw base and jaw proper, showing my improved adjusting and locking screw;

Fi 2 is an end elevation as seen from the right of Fig. 1;

Fig. 3 is a side'elevation of a special key for operating the screw; and

Fig. 4 is an end elevation of the tool shown in Fig. 3 as viewed from the left of the latter figure.

Since my present invention relates entirely to a chuck jaw and its immediate supporting, adjusting and locking means, I have not herein deemed it necessary to illustrate the usual chuck-head; but in the drawing 5 designates the jaw carrier, 6 the jaw base slidably mounted on and relatively to the jaw carrier 5, and 7 the jaw proper secured to the jaw base 6 by the usual ycounter-sunk cap screws 8. 9 designates a jaw operating lever which is pivoted on the usual backplate of the chuck, with its short arm enarm engaged with an endwise movable chuck actuating tube or bar (not shown) that commonly extends axially through the tubular spindle of the chuck, in the manner typically illustrated in Letters Patent to W. L. Miller, No. 1,188,807, June 27, 1916.

In the jaw carrier 5 is mounted for turning movement an adjusting screw comprising two screw sections 10 and 11, the threads of which have the same direction and are of equal pitch. These screw sections are mounted in a tapped lug or boss 12 on the inner face or" the, screw base 6. The screw section 10 has at its out-er end a shank 13 formed with annular shoulders 14 and 15 which are engaged with a coperating ledge or shoulder 16 on the concave face of the jaw carrier, whereby the screw section 10 is permitted a rotary movement but prevented from moving endwise.

The screw section 11 likewise has a shank 17 formed with annular shoulders 18 and 19 which abut against a vcoperating ledge or shoulder' 20 on the concave face of the jaw carrier, thereby permitting rotary, but preventing endwise movement of the screw section 11. j

The` screw section `11 and its shank are formed with an axial boro 21, in which is rotatably mounted a round stem 22 on the opposite end of the screw section 1() from its shank 13. The outer end of the shank 17 of the screw section 11 is formed with a rectangular socket 23, and the outer end of the stem 22 of the screw-section 10 which extends to or slightly beyond the base of the socket 23 is formed with a transverse kerf 24.

Referring to Figs. 3 and 4, I have thereon shown a special tool designed to manipulate the adjusting screw above described; this tool comprising a stem or shank 25, with a handle 26 passed through the head 27 thereof. The inner end of the shank or stem 25 gaged with the jaw carrier 5 and its long has a squared portion 28, and on the inner end of this latter is a flat narrow tongue 29. The squared portion 28 fits the socket 23, and the tongue 29 fits the ker 24.

In the use of the device, to adjust the jaw lengthwise of the jaw carrier the adjusting tool is inserted with the squared portion 28 in the socket 23 and the tongue 29 in the kerf 24. By turning the tool in one direction or the other, both screw sections are simultaneously and equally turned7 and the jaw base and jaw are adjusted inwardly or outwardly toward or from the center of the chuck-head, until the desired adjustment is reached. The adjusting tool is then withdrawn'suiiiciently to retract the tongue 29` from the kerf 24, and is then given a urther turn in one direction or the other, whereby the screw section ll is turned a slight distance relatively to the screw section 10. This tends to force the screw sections lOrand l1 either apart or toward each other, and creates sufficient `friction in the threads of the screw and at the shoulders 16 and 20 to effectively lock the screw against `any accidental turning under the thrust of ried without departing `fromV the principle involved or sacrilicing anyv of the advantages secured. Hence I reserve all such variations and modifications as fall within the spirit and purview of the appended claims.

I claim: Y

l. The combination with a jaw carrier, and a jaw base mounted for endwise movement on said carrier, of anadjusting screw rotatably mounted in said carrier and drivingly engaged with said base, said screw being formed in two independently rotatable sections disposed end to end1 and means whereby said sections may be simultaneously and equally turned in the same direction and whereby also one oiE said sections When it is desired to again adjust the jaw,

'both of said screw sections, vand also adapted,

when partially withdrawn, to engage with and turn said outer key-engaging portion only. i Y

3. The combination with a jaw carrier, and a jaw base mounted-for endwise movement on said carrier, 6I an adjusting screw rotatably Vmounted in said carrier and drivingly engaged with said base, lsaid screwbeing :formed with two sections disposed end to end, one of said sections having an axial bore termniating at its outer end in al key-engaging member, and the other section having a stem mounted in said bore and terminating at its outer end in a keyengag'ing member located inwardly of said iirst-named key-engaging member, and

a key provided with poitionsfadaptedv toV drivingly engage with both said key-engaging members to effect simultaneous equal rotation of said screw sections, and, when partially withdrawn, to engage only withsaid first-named key-engaging member whereby to effect a relative turning movevment of said screw sections to thereby lock said screw against accidental turningi 4. The combination with afjaw carrier,

and a jaw base mounted for endwise movement on said carrier, or" an adjusting screw rotatably mounted in said carrier and drivingly engaged with said base, said screw being formed in two co-axial sections disposed end to end, one of said sections having an axial bore terminating at its outer end in a Y key-engaging socket, and the other section provided with a stem mounted in said boreY and terminating at its outer end in a key- .engaging socket locatedinwardly of said first-named socket, and a key provided with endwise alined socket-engaging portions shaped to iit the respective sockets of said j screw sections.

HANs c. ELvEns. 'Y 

